The present invention is related to the measurement of objects. Although specific reference is made to intraoral scanning of teeth, embodiments as disclosed herein will find application in many fields such as topography and wavefront measurements.
Many dental and orthodontic procedures can benefit from accurate three-dimensional (3D) topographical measurements of a patient's intraoral cavity. For example, in the design and fabrication of dental prostheses (e.g., crowns or bridges), 3D models of the prosthesis site and surrounding dentition are typically used to ensure proper fit of the prosthesis. In many orthodontic procedures, 3D models of the patient's dental arches are utilized to design orthodontic appliances and develop treatment plans (e.g., to correct malocclusions). Various approaches can be used to produce such 3D models. For example, a physical model can be constructed from an impression of the patient's dentition. Alternatively, the intraoral cavity can be scanned to provide a virtual model suitable for use within computer-assisted design and computer-assisted manufacture (CAD/CAM) methods as well as digital treatment planning.
Scanning of the intraoral cavity may be performed by a dental or orthodontic practitioner. Previous methods and systems for scanning the intraoral cavity, however, can be less than ideal with regards to the accuracy and size of the scanning probe that is used to measure the teeth of the patient. Work in relation to embodiments suggests that the formation of light spots with such prior scanning systems can be less than ideal and may be related to measurement noise and less than ideal measurements in at least some instances. The focused spots may comprise artifacts related to the light source such as speckle, and these artifacts can affect measurement accuracy. Also, the size of the hand held probe that is positioned to measure the teeth can be somewhat larger and more difficult to position than would be ideal in at least some instances.
In light of the above, there is a need for improved methods and systems for scanning an intraoral cavity of a patient. Ideally, such systems would be more accurate and easier to manipulate than the prior scanning devices.